Kristina Orehounig's research while affiliated with Empa - Swiss Federal Laboratories for Materials Science and Technology and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (129)
In this study, a methodology was developed to evaluate different retrofit strategies, which allows an estimation of the current and future thermal space heating demand of the approximately 1.8 million residential buildings in Switzerland. The approach is based on a building stock dynamics model that considers new buildings, replacement buildings, d...
This review study evaluates a range of urban energy system planning models/tools (UEPMs) with respect to their capabilities to consider, identify, integrate and scale up renewable energy technology (RET) deployment in cities. Working with local stakeholders, we define twenty weighted evaluation criteria in order to assess UEPM capabilities using a...
Lake-source thermal district networks can efficiently supply heating and cooling to buildings and thus save
energy and CO2 emissions. However, it remains unclear to which degree they are a sustainable alternative at a
larger geographical scale. An evaluation of the potential of developing technically and economically feasible
lake-source district s...
![Fig. 1. Location of building archetypes (edited from [32]).](profile/Emmanouil-Thrampoulidis/publication/366919822/figure/fig1/AS:11431281118983421@1675939936556/Location-of-building-archetypes-edited-from-32_Q320.jpg)
Coordinated large scale building retrofit is one of the most effective approaches not only to reduce the environmental footprint of existing buildings but also to assure that climate goals can be met. Existing bottom-up retrofit approaches become infeasible or lack in terms of accuracy and/or computational cost especially when the scale of applicat...
Energy systems are increasingly exposed to variable surplus electricity from renewable sources, particularly photovoltaics. This study estimates the potential to use surplus electricity for power-to-gas with geo-methanation for Switzerland by integrated energy system and power-to-gas modelling. Various CO2 point sources are assessed concerning expl...
The original intention of daylight saving time (DST) was to save energy required for artificial lighting. This one-hour shift in working hours, however, also impacts the current and future heating and cooling demand of buildings, which is yet to be thoroughly investigated. Here, daylight saving time-induced heating and cooling demand of archetype o...
Efforts to combat climate change involve long-term plans to reduce the energy demand and increase the share of locally generated renewable energy. However, a sudden change in the geopolitical situation may require an even more rapid response to reduce energy imports through energy-efficiency improvements. In the building sector, retrofits to the bu...
Die Studie «Energiezukunft 2050» untersucht mögliche Optionen zum Umbau des schweizerischen Energiesystems und deren Auswirkungen, insbesondere in Bezug auf die Erfüllung der Energie- und Klimaziele der Schweiz. Die Modellierung des Energiesystems wurde im Auftrag des VSE durch die Energiebranche in Zusammenarbeit mit der Empa erarbeitet und analys...
Combining uncertainties of climate and energy models are challenging as they have different resolutions. The inclusion of building and transportation sectors into modelling prompted by the desire to decarbonize those sectors increases the complexity even further, as the uncertainties added by the operation of these sectors can easily amplify the un...
Urban densification increases the number of people living in urban areas and is hypothesized to be a more efficient use of available land than urban sprawl. The objective of this study was to quantify the operational and embodied emissions created as a result of densification. A ‘Business as usual’ and a ‘Concentrated’ densification strategy were i...
Energy demand of buildings forms a key component of energy system analyses. To integrate building energy demand into energy system models, detailed simulation of every single building is however impractical and often computationally infeasible. Simulations are therefore typically performed on a sample of buildings for bottom-up analysis. For simpli...
Energy systems need to decarbonize rapidly whilst satisfying heating and cooling needs. In Switzerland, residential cooling has so far only a small impact on the national energy demand, but climate change and a larger uptake of cooling devices are expected to lead to future increases. This requires novel approaches for sustainable cooling solutions...
Swiss buildings, the majority of which will last beyond 2050, are responsible for a large share of energy demand and greenhouse gas emissions. Hence, building retrofit is considered as one of the most promising approaches to reduce those shares. However, reducing the energy load should not be an end in itself. The continuous integration of intermit...
To design energy access solutions for rural households in developing countries it is important to have an accurate estimation of what their electricity consumption is. Studies reveal that they mainly use electricity to meet their lighting needs, as they cannot afford high power-consuming appliances. However, the scarce data availability and modelin...
This paper investigates modeling methods with thermal network representation under the scope of the optimal design and operation of Distributed Multi-Energy System (D-MES). Two modeling approaches are compared: A Mixed‐Integer Linear Programming (MILP) optimization model and a district heating network (DHN) simulation model. The MILP model was deve...
Although densification of urban areas is being proposed as a sustainable urbanisation strategy, frameworks for detailed large-scale analysis of densification potentials and their evaluation are lacking. A geospatial simulation framework is presented to assess and evaluate densification potentials at the neighbourhood level of already built-up resid...
This paper presents an analysis of the path towards a clean energy transition in rural areas, from the time that households do not have electricity access from any source, to when they get access to the national electricity; considering the intermediate access to an off-grid renewable technology, as well as the post-electrification years. For this,...
The role of cities in reducing global greenhouse gas emissions is rapidly evolving, as evidenced by significant growth in transnational municipal networks and local climate strategy adoption over the past decade. A large number of energy system modeling and planning tools are available to urban energy planners, but the majority of review studies fo...
Der Umbau des heutigen in ein zukünftiges, erneuerbares Energiesystem eröffnet einen schnell expandierenden Lösungsraum. Fachpersonen müssen aus unzähligen Möglichkeiten die am besten geeignete Lösung finden. Dabei braucht es eine Güterabwägung zwischen Zuverlässigkeit, Wirtschaftlichkeit und Nachhaltigkeit. Ihre Arbeit wird heute mit umfassenden D...
In this study, a holistic energy, economic and environmental assessment was performed on a prosumer-based district heating system, including scenarios with varying district size, retrofitting stages and system configurations. A modeling framework was built which comprises a thermal network design and simulation model; a building energy demand model...
The building sector has the highest share of operational energy consumption and greenhouse gas emissions among all sectors. Environmental targets set by many countries impose the need to improve the environmental footprint of the existing building stock. Building retrofit is considered one of the most promising solutions towards this direction. In...
The research project EnTeR analysed the role of technical energy regulations (TERs) in the transformation of the building stock and their integration into the future energy system. The main task was to identify effective measures which can guide stakeholders to achieve CO2-emission targets by means of TER. Based on this, recommendations for future...
Densification is a sustainable urbanization strategy for reducing per capita environmental impacts facilitating the achievement of sustainable cities as outlined in the sustainable development goals.
We have developed a methodology for assessing sustainable densification potentials at a national scale based on urban structure units and perform an a...
![Figure 1. Rolle on the border of Lake Léman in Switzerland [10].](profile/Atd-Perera/publication/345603784/figure/fig1/AS:955914874023936@1604919274130/Rolle-on-the-border-of-Lake-Leman-in-Switzerland-10_Q320.jpg)
![Figure 3. Software workflow of the Ehub Modeling Tool [12].](profile/Atd-Perera/publication/345603784/figure/fig3/AS:955914874003456@1604919274275/Software-workflow-of-the-Ehub-Modeling-Tool-12_Q320.jpg)
The building sector plays a vital role in Switzerland's climate policy. In order to support the energy transition in the building sector, Rolle, a suburban area located along the shore of Lake Geneva is considered in this study to understand the promising future scenarios for integration of renewable energy technologies. The area is clustered into...
Dezentrale Energiesysteme, die vor Ort erneuerbare Energie gewinnen, speichern, umwandeln und verteilen, ermöglichen eine wirkungsvolle Transformation der Energieversorgung. Die Komplexi-tät nimmt zu, kann jedoch mit neuen, mächtigen Planungsinstrumenten und Automationskonzepten beherrscht werden. Die Digitalisierung in den urbanen Gebieten unterst...
In order to achieve the climate goal of net zero greenhouse gas emissions in 2050, there is an urgent need to transform the current energy system. The pace of energy efficiency improvement on the demand side must be accelerated. However, this strategy alone is not sufficient. Today's energy consumers must be supplied exclusively with CO2-free energ...
The energy strategies used to plan future emissions reductions typically have separate strategies for decarbonisation of the transport and building sectors. However, the advent and diffusion of alternative fuel vehicle technologies could result in vehicle transport becoming a major energy load in urban energy systems in addition to heating and elec...
Technical energy regulations are an important measure to reach climate targets. However, with recent developments in new technologies (such as decentralized energy systems, urban energy systems, energy storage systems, etc.) many different options and combination of measures exist to decarbonize the building stock, which requires an update of curre...
The research project EnTeR analyses the role of technical energy regulations (TERs) in the transformation of the building stock and their integration into the future energy system. The main task was to identify effective measures which can guide stakeholders to achieve CO2-emission targets by means of TER. Based on this, recommendations for future...
An optimization model has been built to select the optimal combination of vehicle technologies, charging and building system technologies for a group of 52 buildings and 82 cars in Switzerland. The multi-objective optimization reduces both total costs and total emissions and performs both a selection of vehicle, building, charging and storage techn...
Distributed Multi-Energy Systems (D-MES) can sustainably transform the energy supply of buildings, districts, and communities by integrating multiple energy efficient technologies, renewable energy sources, and electricity, gas, and thermal energy networks to provide heating, cooling and electricity services. However, D-MES typically exhibit high l...
Um mehr erneuerbare Energiequellen in das Energiesystem Schweiz zu integrieren, braucht es neue Konzepte. Das «Energy Hub»-Konzept erlaubt ganzheitliche, techno-ökonomisch optimierte Lösungen zu finden. Am Beispiel «Masterplan Energie Brig-Glis» wird die Anwendung des «Energy Hub»-Konzepts aufgezeigt.
HUBS ÉNERGÉTIQUES: CONTRIBUTION À LA TRANSITIO...
In this work, a model is built to test the optimal design and performance of a multi-energy systems at five different levels of decentralization, ranging from 225 individual buildings systems to a single district system supplying all building’s energy demands. A multi-objective analysis, minimizing both costs and emissions with the epsilon-constrai...
The potential of both long-term (hydrogen storage) and short-term (batteries and thermal) storage systems in decentralized neighbourhoods are assessed using a multi-objective optimization approach that minimizes both costs and CO2 emissions. A method is developed, which evaluates the performance of long and short-term storage systems in the future...
A limited amount of studies has focused on estimating the electricity demand of rural households (HH) in developing countries; and, the scope and application of these are limited to one or a small group of countries. This paper presents a methodology for modelling the electricity demand taking evidence from more than 30,000 rural households in 37 A...
The integration of heat production from solar energy technologies can be realized by feeding in energy both at centralized or at multiple decentralized locations from the consumer side. As distribution networks serve as thermal transmission grids, the interaction between the energy feed in (i.e. production) and withdrawal (i.e. consumption) at mult...
In this work, a model is built to test the optimal design and performance of a multi-energy systems at five different levels of decentralization, ranging from 225 individual buildings systems to a single district system supplying all building's energy demands. A multi-objective analysis, minimizing both costs and emissions with the epsilon-constrai...
Renewable-powered projects such as mini-grids and solar home systems (SHS) are often considered as solutions for rural electrification in the cases where grid-expansion becomes unaffordable and inefficient. However, to reach an optimal system design, project developers need to have an accurate estimation of the electricity demand. Estimating it is...
Uncertainty introduces significant complexity to the design process of distributed energy systems (DES) and introduces the risk of suboptimal decisions when the design is performed deterministically. Therefore, it is important that computational DES design models are able to account for the most relevant uncertainty sources when identifying optimal...
The increasing penetration of renewable non-dispatchable electricity sources into urban energy systems is necessitating the adoption of novel storage technologies to facilitate the temporal matching of energy supply and demand. Power-to-hydrogen (P2H) is one such storage technology option; in which electrolysis is used to convert excess electricity...
The optimal design and operation of an integrated building energy system consisting of the renewable energy technologies such as ground source heat pumps (GSHPs) and solar thermal collectors, etc., is an important problem to be addressed. This paper describes a methodology for the optimization of a building energy system including a detailed therma...
The design of distributed energy systems (DES) is affected by uncertainty, which can render designs suboptimal. DES design is further complicated by the various decision-maker attitudes towards uncertainty, which range between pessimism and optimism. An additional important factor is the risk of extreme outcomes (e.g. high costs) in highly unfavour...
Energy models are valuable tools that are commonly employed for the optimal design of distributed energy systems (DES). However, the model-based design process of DES can be affected by uncertainty, which can lead to suboptimal design decisions and is introduced by aspects like the stochastic nature of renewables or the unknown future global energy...
The effective design of Distributed Energy Systems (DES) is subject to multiple uncertainties related to aspects like the availability of renewable energy, the building energy demands, and the energy carrier prices. Nevertheless, current practices involve the use of deterministic design models, which overlook uncertainty and can lead to suboptimal...
This paper presents the building stock model CESAR (Combined Energy Simulation And Retrofitting), which is based on bottom-up modelling methodology for the development of sustainable energy transformation strategies for the buildings in Swiss districts. CESAR is composed of two sub-models: a Demand Model (DM) and a Retrofitting Model (RM). The DM i...
This work proposes a mixed-integer linear program approach to consider the uncertainty of input data in the optimal design of distributed multi-energy systems involving both conventional and renewable-based conversion technologies, as well as storage units. The design procedure determines the minimum-cost combination of technology selection, size a...
Ground source heat pumps typically use Borehole Heat Exchangers (BHEs), which are drilled vertically into the ground to extract heat. Space limitations in urban areas can limit the total length of BHEs. Continuous heat extraction over long periods from BHEs especially those with restricted lengths, will result in cooling of the ground. Furthermore,...
In this paper, a conceptual district heating networks model is developed for the integration of decentralized renewable energy technologies. The network model is based on thermal hydraulic calculations, which includes the design of the network structure with information of connections as nodes and edges. Additionally, it accounts for networks pipe...
This paper examines the design of autonomous Distributed Energy Systems (DES) under energy demand and solar radiation uncertainty. A two-stage stochastic program is developed that seeks cost-optimal DES designs considering probabilistic scenarios for the uncertain parameters to represent possible operating conditions. Then, energy autonomy constrai...
This study describes an optimization method for the design and operation of a hybrid solar ground source heat pump. The system studied consists of solar thermal collectors, borehole heat exchanger (BHE), a heat pump, natural gas boiler and a stratified daily storage tank. The method uses a single-objective optimization for operation nested within a...
The temporal fluctuation of solar energy resources require often the utilization of thermal energy storage to increase the level of solar energy. Solar energy systems that are used to meet the heating demands of buildings can be implemented in a variety of system configurations, ranging from energy production and storage at the building-level, to c...
In this paper, a method for a multi-objective and simultaneous optimisation of building energy systems and retrofit is presented. Tailored to be suitable for the diverse range of existing buildings in terms of age, size, and use, it combines dynamic energy demand simulation to explore individual retrofit scenarios with an energy hub optimisation. I...
In this paper a mixed integer linear programming (MILP) model is developed to facilitate the design of a solar domestic hot water system. The MILP model does so by optimising the area of roof mounted flat plate solar thermal collectors and the volume of thermal energy storage that are required to minimise the annual capital and operational cost of...
Within the general context of Greenhouse Gas (GHG) emissions reduction, decomposition analysis allows the quantification of the contribution of different factors to changes in emissions as well as the assessment of the effectiveness of policy and technology measures. The Kaya identity has been widely used for that purpose in order to disaggregate c...
URBAN DEVELOPMENT (URBAN PLANNING); ENERGIESPAREN IM BAUWESEN; ENERGY SAVING IN BUILDING; SUSTAINABLE ENERGY SUPPLY (ENERGY TECHNOLOGY); ZERNEZ (KANTON GRAUBÜNDEN); SCENARIOS + MODELS OF THE FUTURE; ZERNEZ (CANTON OF GRISONS); NACHHALTIGE ENERGIEVERSORGUNG (ENERGIETECHNIK); STÄDTEBAULICHE ENTWICKLUNG (STÄDTEBAU); ÖKOBILANZEN + ÖKOLOGISCHE BUCHHALTU...
ENERGIESPAREN (ENERGIETECHNIK); SUSTAINABLE ENERGY SUPPLY (ENERGY TECHNOLOGY); ZERNEZ (KANTON GRAUBÜNDEN); DORFPLANUNG + DORFENTWICKLUNG (RAUMPLANUNG); VILLAGE PLANNING + VILLAGE REDEVELOPMENT PLANNING (PHYSICAL PLANNING); SCENARIOS + MODELS OF THE FUTURE; ZERNEZ (CANTON OF GRISONS); NACHHALTIGE ENERGIEVERSORGUNG (ENERGIETECHNIK); ENERGY CONSERVATI...
We present a comprehensive review of modelling approaches and associated software tools that address district-level energy systems. Buildings play an important role in urban energy systems regarding both the demand and supply of energy. It is no longer sufficient to simulate building energy use assuming isolation from the microclimate and energy sy...
This paper describes a method of integrating decentralized energy systems at neighbourhood scale. The method is based on the energy hub concept, which describes and manages the relation between input and output energy flows and thus can be used to optimise energy consumption. The original energy hub concept is further developed to include decentral...
Buildings are expected to significantly contribute to the adoption of renewables, and mainly solar technologies due to largely unutilised roof space. A framework to assist the decision making process towards the optimal integration of solar energy in urban areas, with the focus on photovoltaic panels, considering spatiotemporal aspects, is presente...
Variations in operational use (in the time domain) and in design and use (between buildings) are critical for district systems. The effects on energy use of behavioural (stochastic profiles of occupancy and end uses) and physical variations (size, orientation, insulation and air tightness) amongst many buildings is examined. Rather than investigati...
